1. Technical Field
This disclosure relates to memory circuit repair, and more particularly to column redundancy repairs.
2. Description of the Related Art
Most memory circuits today implement some type of redundant circuit to repair cells and or logic that fails during manufacturing, or even during operation. Although there is a cost associated with adding the redundant logic, the benefits typically outweigh the cost because as device geometries continue to shrink, the number of defects introduced during manufacturing continues to increase. Accordingly, the cost of the redundant logic is small when compared to the cost of having to discard a device due to a memory failure. This may be especially true when the memory is embedded within a system on a chip (SOC), for example.
Although redundant memory circuits are beneficial, there are sometimes other drawbacks associated with these circuits. For example, in many cases, when a redundant circuit is switched in to repair the damaged circuit, additional delays may sometimes be introduced to the memory critical path. These additional delays may become unacceptable in some instances.